The photo above is from a 2008 Amsterdam art installation created by the Sagmeister group out of 250,000 coins. In the links, you can find a time-lapse video of the creation of the display. The captions read, in part:

Over the course of 8 days, and with the help of over 100 volunteers, the coins were sorted into 4 different shades and carefully placed over a 300 sqm area.

The coin mural spelled out the sentence "Obsessions Make My Life Worse and My Work Better."

After completion the coins were left free and unguarded for the public to interact with.

You missed the best part of the Story, in which the Police busted the Artwork and removed it in the first night. No joke: http://scottburnham.com/2008/09/stefan-sagmeister-installation-removed-by-amsterdam-police/